Video operations include the operations necessary to control video displays to visually communicate computer processes to a user. Typical video operations are performed by a video subsystem under the control of one or more system processors. For example, during video cycles, a processor might transfer display instructions and display data, to be interpreted and ultimately displayed by the video subsystem.
Prior art computer system architecture requires that a system processor refrain from performing other tasks while a video cycle is being performed since the video cycles and other cycles must be performed over the same bus or buses. This results in undesirable system bus bottlenecks during the transfer of video cycles, which can significantly reduce system performance.
What is desired but unavailable in the prior art, is an inexpensive and efficient modification of existing computer systems in which the processor or processors are free to perform other cycles concurrently (i.e., in parallel or simultaneously) with video cycles, and video cycle traffic on system buses is minimized.